Star rating: ****

THE last-ever Triptych Saturday began by illustrating the key flaw of its successor, the fans-choose-the-bands experiment that will be the Tennent's Mutual. Who - other than Mogwai or the staff of the estimable Beard magazine - would suggest the little-known RememberRemember to open a 10-hour music show? Graeme Ronald's web of loops was a breathtaking reminder of why curating is best left to curators.

The rest of the bill was short on surprises but exquisitely assembled. The only quibble being that the acoustic set from arch-miserablist Malcolm Middleton, while gorgeous, might have been better earlier in the evening. It was also a shame that whoever did the live mix for the borderline-godlike Errors apparently had no idea what they're meant to sound like: hear those slabs of skull-splitting synth? No, us neither - but their upcoming album should be one of the year's best. Frightened Rabbit, meanwhile, just get better and better: Celtic drone-folk (to coin a phrase) with - yes - a drum solo.

Watching Clinic power through their angry staccato stomps, a thought occurred: they should be The Fall. Seriously: next time Mark E Smith sacks his band, he should give them a call - and a much-needed kick up the backside. Still a great band, but one desperate for a sense of direction.

I've been writing about Mogwai for 10 years now and have run out of superlatives. After a decade, one could take them for granted; here, though, in a majestic set bravely dominated by new material (all awesome, some transcendent) they were simply monumental. As one of Tennent's rivals might put it: probably the best rock band in the world.

Music Joe Acheson Quartet, Jazz Bar, Edinburgh Rob Adams HHH The quartet part of their name, as with Hammond organ party animal James Taylor, may be arbitrary, and just because there are six people onstage doesn't mean that the Joe Acheson Quartet can't count. There's a metronomic precision as well as a very human pulse to this music, which seems designed to work on different levels simultaneously.

Both danceable and attractively ambient, the compositions of bass guitarist and electronics wiz Acheson draw on a cornucopia of ingredients. Spaghetti western-like trumpet themes, recorded interviews, pizzicato violin figures, a phantom cor anglais, a blast of Blues in the Night, and gurgling electric cello lines emerge from live instruments and samples as the group's engine room and potential focal point - its two-drummers groove - converse and cannily blend marching snare drum patterns with funk fundamentals.

Meanwhile, cityscapes and assorted visuals, courtesy of sixth member Ivan Torres Hdel, complement sounds with appropriate images. An improvising saxophone, as is promised elsewhere in the band's schedule, might have created the spontaneous mood that was missing here, but as it stands there's still much to enjoy about yet another promising outfit on Edinburgh's melting pot of a music scene.